To provide a heat-mode negative type printing original plate for lithographic printing, which can easily process without necessitating a developing treatment and, even the processing under the state being directly installed on a printing machine is possible, is excellent in plate wearability and in which the printing scumming on a printing surface develops a few, which can easily process by an image disposing system by a scanning type with laser rays and is excellent in distinguishability between an image part and a non-image part, and repeatedly recyclable, and the manufacturing method of a printing plate employing the original plate.

A printing original plate has a photosensitive layer, in which photothermal convertible particles and photocatalytic metal oxide particles are dispersed in a bonding resin. A negative type non-processed printing plate is produced by irradiating the original plate with heat-mode image-like lights so as to convert the polarity of the metal oxide layer in order to form an image-like hydrophobic region. The printing original plate is reproduced by irradiating a used printing plate with active lights or heating the used printing plate up to its high temperature hydrophilicity revealing temperature.